// SPDX-License-Identifier: GPL-2.0 #include <linux/kernel.h> #include <linux/types.h> #include <linux/init.h> #include <linux/memblock.h> static u64 patterns[] __initdata = { /* The first entry has to be 0 to leave memtest with zeroed memory */ 0, 0xffffffffffffffffULL, 0x5555555555555555ULL, 0xaaaaaaaaaaaaaaaaULL, 0x1111111111111111ULL, 0x2222222222222222ULL, 0x4444444444444444ULL, 0x8888888888888888ULL, 0x3333333333333333ULL, 0x6666666666666666ULL, 0x9999999999999999ULL, 0xccccccccccccccccULL, 0x7777777777777777ULL, 0xbbbbbbbbbbbbbbbbULL, 0xddddddddddddddddULL, 0xeeeeeeeeeeeeeeeeULL, 0x7a6c7258554e494cULL, /* yeah ;-) */ }; static void __init reserve_bad_mem(u64 pattern, phys_addr_t start_bad, phys_addr_t end_bad) { pr_info(" %016llx bad mem addr %pa - %pa reserved\n", cpu_to_be64(pattern), &start_bad, &end_bad); memblock_reserve(start_bad, end_bad - start_bad); } static void __init memtest(u64 pattern, phys_addr_t start_phys, phys_addr_t size) { u64 *p, *start, *end; phys_addr_t start_bad, last_bad; phys_addr_t start_phys_aligned; const size_t incr = sizeof(pattern); start_phys_aligned = ALIGN(start_phys, incr); start = __va(start_phys_aligned); end = start + (size - (start_phys_aligned - start_phys)) / incr; start_bad = 0; last_bad = 0; for (p = start; p < end; p++) *p = pattern; for (p = start; p < end; p++, start_phys_aligned += incr) { if (*p == pattern) continue; if (start_phys_aligned == last_bad + incr) { last_bad += incr; continue; } if (start_bad) reserve_bad_mem(pattern, start_bad, last_bad + incr); start_bad = last_bad = start_phys_aligned; } if (start_bad) reserve_bad_mem(pattern, start_bad, last_bad + incr); } static void __init do_one_pass(u64 pattern, phys_addr_t start, phys_addr_t end) { u64 i; phys_addr_t this_start, this_end; for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &this_start, &this_end, NULL) { this_start = clamp(this_start, start, end); this_end = clamp(this_end, start, end); if (this_start < this_end) { pr_info(" %pa - %pa pattern %016llx\n", &this_start, &this_end, cpu_to_be64(pattern)); memtest(pattern, this_start, this_end - this_start); } } } /* default is disabled */ static unsigned int memtest_pattern __initdata; static int __init parse_memtest(char *arg) { int ret = 0; if (arg) ret = kstrtouint(arg, 0, &memtest_pattern); else memtest_pattern = ARRAY_SIZE(patterns); return ret; } early_param("memtest", parse_memtest); void __init early_memtest(phys_addr_t start, phys_addr_t end) { unsigned int i; unsigned int idx = 0; if (!memtest_pattern) return; pr_info("early_memtest: # of tests: %u\n", memtest_pattern); for (i = memtest_pattern-1; i < UINT_MAX; --i) { idx = i % ARRAY_SIZE(patterns); do_one_pass(patterns[idx], start, end); } }